Structural active material for battery electrodes

Carbon particles having average particle size of 1-100 mu m are intercalated and mixed with silicon particles having average particle size of 5-500 nm. An amorphous carbon polymer or polymer precursor is added, and mixture is heat-treated in the absence of oxygen in air at temperature at which polymer is decomposed to manufacture electrode active material. Independent claims are included for the following: (1) electrode active material; and (2) electrode.